AMJ Tools

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds real value beyond that by disclosing the returned payload — descriptions, examples, limits, and prices — which matters because there is no output schema. It does not cover behavior for an unknown slug, but with annotations carrying the safety bar this is solid.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

A single compact sentence with no filler, and the return contents are stated up front. The 'Input JSON Schema' clause is the one piece of awkward phrasing that could momentarily mislead.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With no output schema, the description usefully enumerates the response fields, which is the main thing an agent needs. Only minor gaps remain: error behavior for an invalid slug and confirmation that exactly one tool is returned.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100% and the slug parameter is documented in-schema as coming from list_tools, including a format pattern. The description adds nothing beyond that about the parameter, so the baseline 3 applies.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific resource ('one tool') and enumerates what is returned (description, examples, limits, prices), which separates it from list_tools and run_tool. The opening phrase 'Input JSON Schema' is a slightly awkward way to say the tool reads a tool definition, but the retrieval intent is still clear.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Usage is only implied: fetch metadata for a single tool. It never says when to prefer this over list_tools (bulk listing) or run_tool (execution), nor does it state that the slug must come from list_tools, leaving the agent to infer the workflow.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds the useful fact that only "live" tools are returned and lists what each entry contains, but says nothing about ordering, result size, or whether the listing is filtered by caller permissions.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

A single tight clause with no filler, and the content (returned fields) is front-loaded. It is a sentence fragment without an explicit verb, which costs a point but nothing is wasted.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With no output schema, the description must carry the return-value burden, and it does so by naming the five fields returned. Minor gaps remain around pagination/ordering and whether the catalog is scoped, but for a zero-parameter read-only listing this is largely sufficient.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The tool takes zero parameters, so the baseline is 4. The description correctly implies a parameterless bulk listing and does not misrepresent any input options.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description states the scope ("every live tool") and enumerates the returned fields (slug, purpose, category, price per call, endpoint), which makes the resource and output clear. It does not explicitly name a verb or contrast itself with get_tool, but "every live tool" implicitly separates enumeration from single-tool retrieval.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Usage is only implied: an agent can infer this is the discovery/enumeration call, in contrast to get_tool and run_tool. There is no explicit statement of when to prefer this over alternatives, nor any prerequisites or exclusions.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already mark this as non-read-only, open-world, and non-idempotent. The description adds important behavioral context about payment via x402 signature or pass API key and the HTTP 402 response when neither is supplied, which is information the annotations do not provide.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is two sentences, front-loads the core action and schema reference, then covers payment behavior. There is no redundant or filler content.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

The description covers payment requirements and the 402 failure path, which are important. However, with no output schema, it does not describe what a successful call returns, which is a meaningful gap for an execution tool with a nested input object.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so the schema already documents slug, input, api_key, and payment_signature. The description reinforces the payment parameters but does not add syntax, format, or usage details beyond what the schema provides.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description states a specific action and resource: run a tool using an input matching its schema. It references get_tool for the schema, which helps connect it to siblings, but it does not explicitly distinguish its execution role from list_tools/get_tool beyond that reference.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Usage is implied: provide a slug and input, and pay via payment_signature or api_key. However, it does not explicitly say when to choose run_tool versus get_tool or list_tools, nor does it state prerequisites beyond payment handling.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.